Devices installed in a vehicle include devices for switching a process to be executed to another process according to the number of on/off operations of an ignition switch in the vehicle, an example of which is disclosed in Japanese Patent Application Publication No. H11-212784. These devices also include devices for checking a microcomputer's program memory in response to the turn-on of the ignition switch to check whether the microcomputer has an abnormality; this program memory represents a microcomputer's memory area in which programs are stored, an example of which is disclosed in Japanese Patent Application Publication No. H07-042609.
In addition, these devices include devices for executing processes, such as fail-safe processes, to address occurred abnormalities in the vehicle.